The present invention relates to the field of medical instruments. More particularly, the present invention relates to an improved trocar sleeve, and the manner in which a pressurized fluid may be dispersed through the trocar sleeve.
During the performance of certain surgical procedures a surgeon may need to use a needle or a trocar device to deliver fluid into a body cavity, or a portion of a body, for the purposes of inflating or distending the body cavity to make it easier to see and perform the desired treatment. Common procedures in which insufflation is used include any type of an endoscopic surgical procedure, as well as laparoscopic or thoracoscopic surgical procedures performed in the abdominal or thoracic body cavities, respectively. In these procedures a blind incision, for example, or a Verres needle may be used to initially traverse the skin and tissue layers until the body cavity is entered for the purpose of passing a pressurized fluid, either a gas or a liquid, into the body cavity.
If a Verres needle has been used penetrated into the body cavity, an external gas source is attached to a proximal end of the needle projecting outwardly of the body cavity. Under pressure, the desired fluid flows from the proximal end of the needle to a distal end thereof from which the fluid exits and is delivered into the body cavity for inflating the body cavity. When a blind incision is made, a standard trocar assembly may then be passed through the incision and into the body cavity, whereupon the desired fluid is passed through the trocar into the body cavity. In either instance, this process is known as insufflation, in which the desired fluid, as well as any other substances, which may include drugs and anesthetics, is passed under pressure into the body cavity. A commonly used gas for this procedure is carbon dioxide. Depending on the patient""s size, medical condition, the procedure to be performed, and the surgeon""s preference, the gas is flowed into the body cavity at a rate of from 0.1 to 20 liters per minute.
As described, in addition to Verres needles, physicians also use trocars, or trocar assemblies for the purposes of passing a pressurized fluid within a body cavity. The known trocar assemblies have a solid outer sheath or sleeve sized and shaped to be passed through the incision and tissue layers of a body so that the sleeve penetrates at least partially into the body cavity. This is accomplished by passing an elongate central retracting piercing element, referred to as a trocar or an obturator, through the sleeve and then passing the sleeve and the trocar together through the tissue. Once the sleeve is passed into the body cavity to the desired depth, the trocar is withdrawn from the sleeve.
During the insufflation process the gas distends the body cavity to move the tissue layers outwardly of the body to create sufficient space in the cavity to observe or treat the organs and/or body structures therein, and to also move the distal end of the trocar or Verres needle therefrom. Once the body cavity is distended with gas and the obturator of the trocar is withdrawn from the lumen of the trocar sleeve, viewing and surgical instruments are typically passed therethrough, while fluid may be continuing to flow therethrough as well, in order to allow the surgeon to visualize the contents of the body cavity and proceed with the desired diagnostic and/or surgical procedures without damaging the remaining tissues, organs, or body structures within the body cavity.
An example of the known types of trocar assemblies is illustrated in FIGS. 1A and B, in which a trocar assembly 5 is shown being used to gain access to a body cavity 6. The trocar assembly is comprised of a solid outer sheath or sleeve 7 containing within its lumen the trocar 9, the removable piercing element. The trocar is used together with the trocar sleeve to pierce the skin, the subcutaneous tissue, the fascia, the muscle, and the innermost layer of the cavity, collectively referred to as 10, to include the parietal peritoneum or the pleura, respectively, for either the abdominal or chest cavities.
As the trocar is being inserted into the body cavity, a fluid xe2x80x9cFxe2x80x9d from an external source, which may be a gas or a liquid bearing drugs, anesthetics, or other substances placed or mixed within a pharmaceutically acceptable carrier, or any combination thereof, is commonly passed through the access port 11 and transported into the body cavity through the distal end 13 of the trocar sleeve. It is commonplace in procedures of this type that the fluid F will also continue to be passed into the body cavity once the trocar is removed. The access port extends from the proximal end of the trocar sleeve exposed above the skin of the patient. As shown in FIG. 1B, various instruments 14, to include light sources, viewing scopes, graspers, manipulators, irrigators, suction devices, sutures, lasers, coagulators, biopsy devices, clip appliers and needle holders, may be placed through the lumen of the trocar sleeve and into the body cavity for the treatment or procedure to be performed.
Because the trocar sleeve will typically have at least one surgical instrument and/or a viewing device placed within its lumen, the cross-sectional area 15 of the unobstructed lumen available for fluid flow is markedly reduced. The fluid is forced to flow between the outer surface of the instrument(s) within the lumen and the internal surface of the trocar sleeve, which restricts the amount of fluid that may be passed through the trocar sleeve and into the body cavity through a relatively small opening 17 in the distal end of the trocar sleeve. Depending on the flow rate of the fluid at the entrance to the trocar sleeve, and the diameter of the sleeve and the restriction(s) within the sleeve reducing the effective fluid transport diameter, the stream of fluid passed from the distal end of the trocar can be quite forceful and is oftentimes formed into a xe2x80x9cjetxe2x80x9d stream 18 of a highly concentrated flow rate at a relatively high fluid velocity. This in turn defines an impact site for the tissues/organs impinged by the jetted fluid, and also limits the dispersion of the agents contained within the fluid stream within the body cavity.
The problem this jet streaming causes is that the jet streamed fluid may cause severe local heat loss from the lining of the body cavity 19 (FIG. 1A) and the surfaces of the organs housed therein as the fluid contacts those tissue surfaces. This phenomena is discussed in greater detail in the paper entitled xe2x80x9cSevere Local Hypothermia From Laparoscopic Gas Evaporative Jet Cooling: A Mechanism To Explain Clinical Observations,xe2x80x9d authored by R. I. Gray, D. Ott, A. C. Henderson, S. A. Cochran, and E. A. Roth, in the Journal Of The Society Of Laparoendoscopic Surgeons for August, 1999.
Because of these problems associated with the known types of trocar assemblies and sleeves, namely the postoperative hypothermia and suboptimal dispersion of therapeutic agents within the body cavity resulting from this jet streaming, there exists a great need for a trocar sleeve that will minimize or eliminate these jet streaming effects, to include limiting the possibility of damaging tissues and organs within the body cavity while efficiently dispersing the desired fluids through the trocar sleeve and into the body cavity at reduced fluid pressures.
The present invention provides an improved trocar sleeve adapted to minimize the likelihood of forming a jetstream of the fluid being passed through the sleeve and into a body cavity, and which will more efficiently disperse the fluids in the body cavity. The trocar sleeve of this invention provides a simple and efficient device, system, and method for efficiently and safely passing a fluid into a body cavity during a surgical procedure. Moreover, the relative simplicity of the improved trocar sleeve of this invention addresses the problems of efficiently and effectively introducing fluids into a body cavity during the performance of a surgical procedure requiring the insulation of a body cavity.
The invention provides an improved trocar sleeve for insertion into a body for use in delivering a pressurized fluid stream carrying one or more agents under pressure into the body. The device includes an elongate tubular body member formed about a longitudinal axis, having a proximal end and a spaced distal end. An inlet port is defined at the proximal end of the body member, and an outlet port is defined at the distal end thereof. Together the inlet port and the outlet port, in cooperation with the body member, define a fluid conduit extending substantially the length of the body member. A plurality of spaced openings are defined in the body member and open into the conduit, the openings extending from the distal end of the body member at least partially toward the proximal end thereof. The fluid to be delivered into the body is passed through the body member and dispersed through these openings in an arc extending radially about the axis of the body member.
The plurality of spaced openings defined in the body member may be randomly spaced, or regularly spaced, as desired. In one embodiment, a series of recessed dimples is formed in the exterior surface of the trocar sleeve, the plurality of spaced openings being defined within separate ones of these dimples. In another embodiment, a continuous helical groove is defined within the exterior surface of the body member extending from the distal end thereof at least partially toward the proximal end of the body member, and within which the openings are defined.
As described, the fluid is passed through the openings defined in the trocar sleeve and into a radial arc about the body member, which arc may be of any desired degree. This may include, therefore, an arc of approximately one hundred eighty degrees, or an arc of three hundred sixty degrees, as desired.
The openings defined in the trocar sleeve are in the range of from 0.01 millimeter to approximately 5 millimeters in diameter. These openings may vary in size as they extend along the length of the body member, either increasing or decreasing in size as they extend from the distal end toward the proximal end of the body member.
The openings defined within the exterior surface of the trocar sleeve may be shaped to be circular, elongate, or of any desired shape. Where elongate, the openings may be formed parallel to the axis of the body member, perpendicular thereto, or parallel to one another and aligned at an angle with respect to the axis of the body member.
The device may further include an elongate tubular inner sheath constructed and arranged to slide within the conduit of the body member, and at least partially along the length thereof. The tubular inner sheath is used to selectively open and close selected ones of the plurality of openings defined within the trocar sleeve.
The improved trocar sleeve of this invention also results in a novel system for reducing the pressure of, and also radially dispersing, a delivered pressurized fluid stream carrying one or more agents into a body. The system comprises the above-described trocar sleeve, a pressurized supply of the fluid to be passed into the body through the sleeve, and a device for introducing the fluid into the body member of the trocar sleeve.
Similarly, a unique method of delivering a pressurized fluid stream carrying one or more agents under pressure to a body also results from this invention. This method includes the steps of inserting a distal end of a tubular body member into the body, passing the fluid to be delivered into a proximal end of the trocar sleeve, and dispersing the fluid from the trocar sleeve and into the body through a plurality of spaced openings defined in the trocar, the plurality of openings extending from a distal end of the body member at least partially toward the proximal end thereof, through an arc extending radially about the axis of the body member.